In automotive fuel tanks, it is common practice to utilize a fuel pick-up device with or without an intake fuel pump and also supporting a fuel level indicating mechanism. The fuel indicating mechanism typically has an elongated rod with a free end supporting a float which moves along with changes in fuel levels. The other end of the rod is pivotally mounted to an indicating or sensor mechanism. The indicating mechanism typically includes an elongated electrical resistance grid and a contact pad which moves with movements of the float and rod as the fuel level changes. The movement of the contact pad along the resistance grid changes electrical characteristics of a circuit thus providing a variable input to a fuel indicator gauge located within the passenger compartment of the associated vehicle.
The aforedescribed fuel indicators or sensors within the fuel tank are generally known. An example of such an indicator is found in U.S. Pat. No. 4,114,130 which discloses the aforementioned pivotal rod, and elongated resistance grid, and a contact pad moveable along the resistance grid corresponding to fuel level changes. In this patent, the contact pad is supported by a member fastened to a portion of the float carrying rod.
An early fluid level gauge is disclosed in U.S. Pat. No. 903,212 which utilizes a pivotally mounted rod carrying a float at one end. In this patent, the float rod extends directly into a fluid level indicating gauge. Thus the aforementioned elongated electrical resistance grid and contact pad are not utilized. Of course, a remote indication of the fluid level in the tank is not anticipated with this arrangement.
Another level sensor or indicator is disclosed in U.S. Pat. No. 4,557,144. In this patent, a float is supported by a pivotal rod which extends into a sensor or indicating assembly. An arm attached to the rod supports a contact moveable along a resistance grid. A spring clip arrangement is utilized between the housing and the contact bearing arm so that axial deviations are eliminated thus maintaining good electrical contact.
The aforementioned patents all utilize a float supported by a pivotal rod for following changes in liquid levels within the fuel tank. However, in these patents there is no accurate and convenient manner of adjusting the angular relationship between a float carrying rod and the position of a contact bearing member relative to an elongated grid. This relationship is important for calibration of the indicating mechanism and to produce a desired output corresponding to both low fuel levels and a high fuel levels. It is particularly desirable to provide a means to calibrate the mechanism after assembly to produce a desired output corresponding to a predetermined position of the float and rod.